Acoustiblok’s All Weather Sound Panels are great for industrial noise problems as they both block and absorb noise occurring indoors and outdoors. With Acoustiblok and QuietFiber as blocking and absorbing materials, panels have an NRC (noise reduction coefficient) of 1.0 and a high STC (sound transmission class) of 30. Acoustiblok, Inc.,, (813) 980-1400. Circle 252Acoustiblok_300px.jpg